题干
They usually spend two hours _______ their homework every day.
A：do
B：doing
C：to do
答案(点此获取答案解析）
B
They usually spend two hours _______ their homework every day.
A：do
B：doing
C：to do
r_ _er
pen_i_ c_ _e
c_a_on
s_h_ol_a_
r_b_er